How to check whether the result of an Ansible task is the same on all the servers?

Question

As part of an Ansible playbook, I want to verify whether my servers are in sync.

To do so, I execute a script on each of my servers using the shell module and I register the result into a variable, say result_value.

The tricky part is to verify whether result_value is the same on all the servers. The expected value is not known beforehand.

Is there an idiomatic way to achieve this in Ansible?

Answer 1

One of possible ways:

---
- hosts: all
  tasks:
    - shell: /usr/bin/my_check.sh
      register: result_value
    - assert:
        that: hostvars[item]['result_value'].stdout == result_value.stdout
      with_items: "{{play_hosts}}"
      run_once: true